This invention generally relates to vehicle throttle controls. More particularly, this invention relates to controlling an electronic throttle control to ensure proper performance.
Vehicle throttle bodies typically include an air intake opening. A blade is typically positioned within the opening and moved between opened and closed positions to control the amount of air intake. Conventional arrangements include mechanical linkages and springs to manipulate the position of the blade responsive to movement of the accelerator petal.
More recently, alternative arrangements have been proposed. One proposal by the owner of this application has been to replace the mechanical linkages and springs with an electronic throttle control arrangement. One challenge facing the designers of such arrangements is how to accommodate situations where there may be interference with proper operation of the assembly for moving the blade into a desired position. One example scenario is when ice forms on the blade or the throttle body. It is necessary to be able to generate enough force to overcome the impediment presented by ice.
There is a conflicting concern between generating sufficient force while maintaining components within the limited space available for the throttle body assembly. Additionally, vehicle suppliers are constantly striving to minimize the cost of vehicle components.
This invention provides an arrangement that utilizes a relatively small electric motor, controlled in a desired fashion, to free up frozen throttle components in the event that ice forms on one or more of the components.
In general terms, this invention is an electronic throttle body control system that is capable of overcoming any difficulties presented by ice formation on one or more throttle assembly components. A system designed according to this invention includes a throttle body having an opening. A blade portion is supported within the body opening and selectively positioned to control air flow into the opening. An electric motor assembly provides a motive force to move the blade portion. A controller controls operation of the electric motor assembly such that the motor and blade portion move rapidly and at a selected frequency for a selected period of time in the event that ice is present.
The preferred embodiment includes making a temperature determination to ensure that a difficulty in moving the blade portion is likely caused by the formation of ice on one or more throttle assembly components. The preferred embodiment also includes inducing motion within the throttle assembly at a first frequency if the blade is frozen into an open position but inducing motion at a second frequency if the blade is frozen in a closed position.
The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows.